Planar (or flat-plate) and conformal antennas for high frequency microwave transmission (e.g. in various parts of 0.1-40 GHz range) are nowadays widely in use, for example in radio broadcasting, mobile communication, and satellite communication. Such antennas can provide circular and linear polarization, based on their specific configurations.
Generally, printed conformal and planar antennas are built on a multilayered substrate structure (e.g. PCB, printed circuit board) and include, inter alia, a dielectric substrate and an array of radiating elements and their respective transmission lines, the number of elements depending on their gain as well as on the overall desired gain of the antenna. The radiating elements and the transmission lines are disposed on either one or both sides of the dielectric substrate. Planar antennas are produced, for example, by printing using so-called “microstrip” technology or photolithography.
U.S. Pat. No. 6,285,323 discloses a flat panel antenna for microwave transmission that comprises at least one PCB, and has radiating elements and transmission lines located on both the first and second sides of the PCB in a complementary manner, such that the transmission lines of the first and second sides overlay one another, and the radiating elements of the second side extend outwards from the terminations of the transmission lines in the opposite directions, at an angle of 180 degrees from the radiating elements of the first side.
US Patent Application No. 2003/0218571 discloses an antenna having linear and circular polarization, which uses dipoles as radiating elements, and has an orthogonal characteristic in both linear and circular polarization, the antenna being embodied in the use of two plates, including the front and rear sides of both plates.
US Patent Application No. 2003/0020665 discloses a planar antenna having a scalable multi-dipole structure for receiving and transmitting high-frequency signals, including a plurality of opposing layers of conducting strips disposed on either side of an insulating (dielectric) substrate.
U.S. Pat. No. 6,163,306 discloses a circularly polarized cross dipole antenna comprising a first L-shaped dipole antenna element including a first pair of strip conductors and a first bending portion and a second L-shaped dipole antenna element including a second pair of strip conductors and a second bending portion. The first L-shaped dipole antenna element is arranged in a first region of four regions delimited by crossing lines virtually set within a single plane and the second L-shaped dipole antenna element is arranged in a second region thereof, which is diagonally opposite to the first region. The first bending portion and the second bending portion are close and opposite to each other, such that the first and second L-shaped dipole antenna elements form a cross. The antenna also comprises a parallel-twin-line feeder extending from the first and second bending portions and provided so as to feed power within the single plane.
Also related to planar antennas are U.S. Pat. Nos. 5,708,446, 5,786,793,6,037,911, 6,166,702, 6,275,192, 6,424,311, 6,518,935, 6,844,851; US Patent Application No. 2003/0063031; PCT Patent Application No. WO01/80358; EP Patent Applications Nos. EP0920074 and EP1271692; and SASAS DRAGAS and MARCO SABBADINI: “A Novel Type of Wide Band Circular Polarised Antenna (Proceedings ESA WPP-222; 27th ESA Antenna Workshop on Innovative Periodic Antennas, Electromagnetic Bandgap, Lefthanded Materials, Fractal and Frequency Selective surface, 9-11 Mar. 2004, Santiago de Compostela.
There is a need in the art for a new planar/conformal antenna.